1. Field of the Invention
The present invention relates to a tape carrier type semiconductor device and a manufacturing method thereof. The present invention relates also to a flexible substrate.
2. Description of the Related Art
A tape carrier type semiconductor device is employed, for example, in a liquid crystal display of notebook computers.
For example, as shown in FIG. 10A, a tape carrier-type semiconductor device 61 is formed by a flexible substrate 62, on which a driver IC 63 for driving a liquid crystal display is mounted.
The flexible substrate 62 has folding slits 66 and a stress-releasing slit 67.
The tape carrier type semiconductor device 61 is folded positions where the folding slits 66 are formed. One end of the tape carrier type semiconductor device 61 is connected to a liquid crystal panel, and the other end thereof is connected to a print substrate to be arranged on the back surface of the liquid crystal panel.
The stress-releasing slit 67 is formed to prevent the tape carrier type semiconductor device 61 from being detached from the print substrate. Particularly, the stress-releasing slit 67 releases mechanical stress put on the connection part of the tape carrier type semiconductor device 61 and the print substrate.
Wiring is formed on the flexible substrate 62, so that the driver IC 63, the liquid crystal panel, and the print substrate are electrically connected. A resin for preventing breakage of wiring is applied onto one surface of the flexible substrate 62, while a solder resist for preventing a short circuit between wiring pieces, which may be caused by the solder, is applied onto the other side surface of the flexible substrate 62.
The resin and the solder resist applied onto the flexible substrate 62 have different heat expansion coefficients. Hence, the tape carrier type semiconductor device 61 may be warped, as shown in FIG. 10B, as a result of heat applied thereto while manufacturing the tape carrier type semiconductor device 61.
If the tape carrier type semiconductor device 61 is dramatically warped, the tape carrier type semiconductor device 61 may be in contact with an arm for connecting the tape carrier type semiconductor device 61, the liquid crystal panel, and the print substrate. If this interference occurs, the tape carrier type semiconductor device 61, the liquid crystal panel, and the print substrate may not desirably be connected.
A technique for preventing such a warp in a tape carrier type semiconductor device is disclosed Unexamined Japanese Patent Application KOKAI Publication No. H5-190593.
According to the technique disclosed in the publication, in order to prevent the warp in the tape carrier type semiconductor device, it is necessary to newly form a slit, and to attach a reinforcement plate, which is harder than the flexible substrate, to the tape carrier type semiconductor device.
The problem in the technique of the above publication is that the tape carrier type semiconductor device is more likely to be warped, since a new slit is formed. In addition, because a reinforcement plate is additionally attached thereto, the number of parts in the tape carrier type semiconductor device increases, and the number of processes for manufacturing the same increases, as well.
The entire contents of the above publication are incorporated herein by reference in its entirety.